#define   _CRT_SECURE_NO_WARNINGS 1
char* my_strncpy(char* destination, const char* source, size_t num)
{
	assert(destination && source);
	char* des = destination;
	while (num) 
	{
		num--;
		if ((*destination++ = *source++) != '\0') 
			;
		else
			break;
	}
	while (num) 
	{
		num--;
		*destination++ = '\0';
	}
	return des;
}